Blast machine enclosure



Aug. 2 1, 1962 Filed NOV. 29, 1960 FIG. l

A. H. FREEMAN BLAST MACHINE ENCLOSURE 4 Sheets-Sheet 1 INVENTOR. ARDEE HORACE FREEMAN ATTORNEYS Aug. 21, 1962 A. H. FREEMAN 3,049 837 BLAST MACHINE ENCLOSURE Filed Nov, 29, 1960 4 sheets-sheet 2 INVENToR. mi' ARDEE HORACE FREEMAN Aug. 21, 1962 A. H. FREEMAN 3,049,837

BLAST MACHINE ENcLosURE Filed Nov. 29, 1960 4 Sheets-Sheet 3 FIG. 7

fl-la INVENTOR. ARDEE HORACE FREEMAN @ME M, @f (7%.

A TORNE YS Aug- 21, 1952 A. H. FREEMAN BLAST MACHINE ENcLosuRE 4 Sheets-Sheet 4 Filed NOV. 29. 1960 INVENIOR ARDEE HORACE FREEMAN Patented Ang. 21, 1962 free 3,049,837 BLAST MACHDJE ENCLSURE Ardea Horace Freeman, Granger, Ind., assignor to Bell Intercontinental Corporation, South Bend, Ind. Filed Nov. 29, 1960, Ser. No. 72,359 11 Claims. (Cl. 51-13) This invention relates to a machine in which abrasive particles are thrown at high velocity upon work continuously being tumbled within a confined space to clean the surfaces of the work, as in the removal of sand from metal casting or burrs and flashing from molded parts, and it relates more particularly -to a blasting machine of this type embodying improvements in the door and closing plate assemblage thereof.

More specifically, the present invention resides in the improvement in the door and closing plate assemblage of centrifugal blasting machines of the type exemplified in Patent No. 2,918,758, and in general, the present invention relates to improvements wherein the closing plate is in the form of a tlat, rigid member moving in a straight path rather than a ileXible member moving in a curved path in accordance with the prior art practice.

Still further, ythe present invention envisages a door and closing plate combination wherein certain features of the door incorporate means protecting the closing plate from damage.

In accordance with the present invention, a primary objective thereof is to provide means whereby the door and closing plate assemblage of a centrifugal blasting machine is so constructed as to be longer lived than conventional prior art mechanisms corresponding thereto. With prior art machines of this nature wherein the closing plate followed a curved path and of necessity was of ilexible nature, it is common for castings or small parts -to become lodged between the conveyor chain and the closing plate. Thiscauses tearing of the rubber portion of the closing plate or bending or damaging of the metal portion thereof. With the present invention, using a straight line closing plate, the closing plate itself may be made of much more rugged form so that the above-mentioned damage does not occur with a closing plate in accordance with the present invention. In conjunction with this, the door in accordance with the present invention utilizes a dam or baille member cooperable with the conveyor chain mechanism tending to obviate the lodging of small parts between the conveyor chain and the closing plate, further enhancing the longevity of the latter.

A further object of this invention is to provide an improved closing plate mechanism for centrifugal blasting machines in which the mechanism for eecting the movement of the closing plate is located wholly outside the conlines of the machine portion in which the abrasive action occurs, preserving such mechanism from damage by the the abrasive atmosphere.

A further object of this invention is to provide an irnproved door for centrifugal blasting machines wherein the dam or baille member as aforesaid cooperates to provide an air baflle whereby air enters the machine through the door itself, but behind the baille or dam member associated therewith such that the clogging of the air openings by abrasive dust is largely obviated.

With the above, and other objects in View that will hereinafter appear, the nature of the invention will be more clearly understood by reference to the following detailed description, the appended claims, and the several views illustrated in the accompanying drawings.

. In the drawings:

FIGURE 1 is a vertical section taken through a portion of a centrifugal blasting machine and showing the closing CII plate and door as constructed in accordance with the present invention;

FIGURE 2 is a view similar to FIGURE 1, but showing the closing plate and door in the open position;

FIGURE 3 is a front elevational View partly broken away and in section illustrating details of the closing plate and door in accordance with the present invention;

FIGURE 4 is an enlarged sectional view taken through the door and illustrating the hinged mounting for the baille or dam member;

FIGURE 5 is an enlarged horizontal section taken substantially along the plane of section line 5-5 in FIGURE 3, illustrating the channel or guide means for the door;

FIGURE 6 is an enlarged vertical section taken substantially along the plane of section line 6-6 of FIGURE 3, illustrating a portion of the operating mechanism for the closing plate;

FIGURE 7 is a sectional view taken substantially along the plane of section line 7 7 in FIGURE 6, illustrating the guide means for the closing plate and also illustrating a part of the operating mechanism for the closing plate;

FIGURE 8 is a partial section taken through the closing plate and illustrating a modied operating mechanism therefor;

FIGURE 9 is a front elevational View of the assembly shown in FIGURE 8;

FIGURE 10 is a view similar to FIGURE 8 but showing a further modication of the operating mechanism; and

FIGURE 11 is a fragmentary plan view taken along the plane of section line XI-XI in FIGURE 10 and illustrating the manner of guiding the closing plate.

Referring now more particularly to FIGURE 1, the reference character il) designates in its entirety the door of the centrifugal blasting machine, and the reference character 11 indicates in general and in its entirety the closing plate for the machine cooperable with the door 10 and including the mechanism indica-ted generally by the reference character 12 for effecting the opening and closing motion of the closing plate.

The details of the blasting machine itself form no part of this invention, but for the purpose of clarity, such mechanism is in accordance generally with the disclosure of Patent No. 2,909,012. Generally speaking, the machine includes, as is shown in FIGURE 1 in dotted lines therein, a conveyor chain 13 entrained over a front shaft and pulley arrangement 14 so as to provide immediately rearwardly of such portion 14 a barrel portion of the conveyor chain in the upper flight thereof upon which are supported the articles to be cleaned. Mechanism, not shown, is provided which throws abrasives onto the surfaces of the articles supported by the barrel portion of the conveyor chain as the same is moved in the direction of the arrow 15 in FIGURE 1. The movement of the conveyor chain is such as to tumble the articles so that all surface areas thereof during the course of the abrasive cycle are exposed to the abrasives thrown thereagainst.

The door 10 in accordance with the present invention includes an outer panel having upper and lower portions 16 and V17, with the lower portion having an outwardly and upwardly angulated lip 18 forming, in conjunction with the lower edge 19 of the upper panel portion 16 a slot Z0 for the entrance of air into the interior of the blasting chamber. A dellector plate 21 having an angulated upper edge 22 joined generally along the lower edge 19 of the panel 16 is rigid with the door and the main body portion of this deilector 21 is generally parallel to the lower panel portion 17 of the door, substantially as is shown in FIGURE 1, and provides a channel for the incoming air directing the same downwardly so as to impinge against the downwardly and inwardly angulated lower edge portion 23 of the lower outer panel 17. The upper and side edges of the door are framed by angle members 24 and '25, and the lower edge thereof is framed by a ilat strip 26, see FIGURES 1 and 5. Journaled between the side angles 2'5 is a pivot shaft 2S which extends along behind the upper panel portion 16 and which projec-ts beyond one of the angle members 25, as is shown in FIGURE 3, and has rigidly aixed to such free end an arm 29 or lever projecting outwardly from the shaft 23 and which has attached thereto a tension spring member 30 anchored at its lower end 31 to a suitable bracket 32' rigid with the door structure. Removably mounted on this shaft 28 is a baie plate 32 provided with vertical and horizontal reinforcing members 33 and 34 rigidifying the same.

It is important to note in conjunction with the baille 32 that the lower edge 35 of the same, when the door 10 is in the closed position, clears the conveyor chain 13 by only a very slight amount, as, for example, '1A inch, so that the baille 32 provides a darn whereby small articles or castings supported on the conveyor chain 13 and being tumbled thereby are substantially prevented from being lodged forwardly of the front shaft and sprocket assembly 14 so as to become wedged between the conveyor chain and the closing plate 11 or between the conveyor chain and the door assemblage 10.

Referring to FIGURE 4, is is preferred that a bracket 36 be xed to one of the angle members 25 of the door carrying an adjustable screw 37 and an associated lock nut 38 whereby the screw forms a stop engageable with the under edge 39 of the arm 29 so as to adjustably limit the positioning of the bathe 32 when the door is in the closed position, so as to adjust for the clearance between the door edge 35 of the bafle and the conveyor chain 13.

The door includes a top seal assembly, indicated generally by the reference character 40, which includes a channel member 41 rigidly secured between the upper clude cables or other flexible elements such as the cable 44 attached through a suitable fastening member 45 and bracket 46v to the upper seal 40.

The channel 41 carries at its ends rollers, see FIGURE 4, indicated therein by reference character 47 which operate in guide channels 48 and a combined seal and guide r is provided along the opposite side edges of the door 10. Such combined seal and guide is best illustrated in FIG- URE 5, wherein it will be seen that the door is provided with a plate 50 which extends outwardly beyond the vertical side framing members 25 and is provided along its vertical side edges with the angle members 51 located within the contines of the angle members S2 and 53 carried by and rigid with the main body portion of the blasting machine, such angle members 52 and S3 providing a channel 54 within which the angles `51 are located. Such construction provides a tortuous battle tending to confine the abrasive atmosphere to the interior of the blasting machine. The edges of the plate 50 may be provided with wear strips 56 substantially as is shown in FIGURE 5.

A portion of the plate 50 extends in overlapping relationship to the outer upper panel portion 16 of the door assembly 10, as is indicated by the reference character 57 in FIGURE l, the lower edge 58 of this portion of the plate terminating closely adjacent to the detlector 32 when the same is inthe normal position when the door is closed, as is shown in FIGURE l.

Preferably, the interior of the plate 50 is lined with resilient material 59 and it will be noted that the lower edge 60 of such material projects beyond the contines of the door assemblage 10 for cooperation with and contacting engagement with the closure plate 11 so as to provide a seal at such juncture.

Insofar as the closure plate 11 is concerned, the same consists essentially of a flat, rigid plate suitably rigidiled and reinforced as by element 66, which element may also conveniently provide a stop or limit means engageable with a frame portion 67 of the machine when the closing plate is in the open position, see particularly FIGURE 2.

The opposite side edges of the plate 65, see particularly FIGURE 7, carry angle members 70 and a wear strip 71 operating within the channels 72 formed between angle members 73 and 74 carried by the abrading machine to provide seals and guides for the plate thereat. Conveniently, the machine frame member 67 rotatably mounts a shaft 78 by means of suitable brackets 79, see particularly FIGURE 6, the opposite ends of this shaft being provided with sprocket members 86 over which a chain 81 is trained. Spaced from the shaft 78 is a further shaft 82 journaled at its opposite ends on the opposite side standards 33 of the machine and aligned with the sprockets 80 are further sprockets 84 on this shaft 82 over which the chain 31 is also trained. The chain 81 is xed to the plate 65, see particularly FIGURE 6, through the intermediary of brackets 86, see also FIGURE 7, which brackets are joined to the links of the chain by means of the link pins 37.

A fluid motor, indicated generally by the reference character 88, is mounted on a suitable frame member 89 and includes a piston and cylinder assembly 90, the piston being provided with an extension or rod 91 extending from the assembly and attached pvotally, as at 92, to an arm 93 rigid with the plate `65. The fluid motor 88 is reversible in operational direction, and is capable of moving the plate 65 between the closed Iand open positions shown respectively in FIGURES l and 2. Due to the fact that the brackets 86 are attached to the chains 81, the plate 61 is prevented from binding or cocking within its guide channels 72, and the plate, therefore, will be constrained to follow a uniform path.

It `will Ibe noted that the existence of the balle 32 permits of this member to be made of highly abrasive resistant material, such as manganese steel, and which is replaceable so that the door assembly may be enhanced in its longevity. Likewise, i-t is simple and convenient to `form the plate 65 of manganese steel so it is also characterized Iby its longevity in use. Also, the entire operating mechanism for the closing plate 11 is situated outside of the abrasive chamber of the machine, and consequently, it is not exposed to -the deteriorating action of the abrasive atmosphere such as is prevalent in prior art devices of this nature.

The operation of the device can be seen from FIG- URES 1 and 2. In FIGURE 1, the door and closing plate are in closed position. When it is desired to open the machine, the door 10 is iirst raised and then the closing plate 11 is lowered so that both assume ultimately the position shown in FIGURE 2. When the assemblage is desired to be closed, the closure plate is trst moved up and then the door moves down. It will be noted, however, that in the opening movement of the door 10, the battle or dam `32 is cammed out of the IWay by the frame member `43 of the machine, and then when the door is closed again, the spring 30 will urge the member 32 to assume its normal position. However, in the case that the spring 30 is not strong enough to fully open the plate 32, or move it to its normal position as illustrated in FIG- URE 1, movement of the conveyor chain 13 will eiect this full opening of the bale or dam member 32.

It is to be noted that the bafe member 32 terminates short of the opposite sides of the machine so that the air entering through the channel or slot 20 can move downwardly and into the machine and around the sides of the baile 32. The baille itself not only prevents the movement of small pieces into lodged relationship in the forward portion of the machine, but it also prevents abrasive dust `from clogging up the passage for the incoming air, effectively shielding the same from direct engagement by abrasive dust.

A modified form of actuating or operating mechanism for the closing plate is shown in FIGS. 8 and 9. In these gures, the closing plate is indicated by reference character 100 .and the machine in general Iby numeral 102. The frame of the machine includes the cam member 104 which mounts, through suitable brackets 106 and 108, an operating shaft 110. This shaft, as can be seen in FIG. 9, extends to gear reduction unit 112. driven by a suitable motor 114 whereby the shaft 110 is rotatable in either direction.

A pair of drums 116 and 118 are fixed to the operating shaft 110 and rotate therewith, it being Ipreferred that the drums be `disposed closely adjacent the respective brackets 106 and 108 as shown. A length of cable, 1Z0 or 122, is associated with each duim, each such length being lwrapped one or more times about its respective drum to extend tangentially therefrom in opposite direction for dead-ending at the upper and lower edges respectively of the closing plate. The two drums and cables, being widely spaced, effectively guide the closing plate on opening and closing movements thereof as imparted by shaft 110 and effectively prevent the closing plate from locking or otherwise deviating from proper movement. This particular type of operating mechanism is particularly well adapted for use in conjunction with large machines having relatively wide, massive closing plates.

A further modification of the operating mechanism is shown in FIGS. l and l1. In this case, the mechanism is particularly well suited for smaller machines in which the closing plate 130 is smaller and less massive. The power means for opening and closing the plate 130 is a fluid motor 132 pivotally connected as vat 134 to a suitable structural member 136' of the machine and having the free end of its piston rod 138 pivotally connected, as at 140, to arm 142 rigid with the closing plate 130. The arm is provided with a relatively wide base portion 144 t0 provide stable engagement with the plate 130. To guide the plate 130 to ride smoothly between the jamb members along opposite sides thereof, the plate is provided with an extending bar or tongue 146 welded or otherwise attachecl thereto so as to extend in longitudinal alignment therefrom and in sliding relation between a pair of vertically standing parallel guide plates 14S-14S rigidly mounted upon cross supports 150. Thus the bar 146 guides the plate 130 to slide at all times in properly aligned attitude, thereby preventing the latter `from binding in its required sliding action as explained hereinabove.

What is claimed as new is:

l. In a centrifugal blasting machine having a frame, a closing plate and access door assembly movably mounted on said frame, said closing plate being in the form of a rigid, at plate and being movable in a rectilinear path relative to said frame, said door being also movable in a rectilinear path relative to said frame with the -two such paths intersecting to define a V-shaped crotch therebetween.

2. In a centrifugal blasting machine having a frame, a conveyor chain and a .front shaft assembly over which the conveyor chain is trained, a closing plate and access door assembly movably mounted on said frame, said closing plate and access door being guided on said frame for rectilinear movement relative thereto and along paths intersecting closely adjacent said front shaft assembly, and dam means on said access door for precluding movement of work pieces from supported position on said chain to positions forwardly of such means whereby to lodge between the conveyor chain and the closing plate and access door.

3. In a centrifugal blasting machine having a frame, a closing plate and access door assembly movably mounted on said frame, said closing plate being in the form of a rigid, at plate and being movable in a rectilinear path relative to said frame, said door being also movable in a rectilinear path relative to said frame with the two such paths intersecting to define a V-shaped crotch therebetween, means for moving said closing plate between open and closed positions, said means being disposed wholly outside the interior of the machine.

4. In a centrifugal blasting machine having a frame, a conveyor chain and a front shaft assembly over which the conveyor chain is trained, a closing plate and access door assembly movably mounted on said frame, said closing plate and access door being guided on said frame for rectilinear movement relative thereto and along paths intersecting closely adjacent said front shaft assembly, and dam means on said access door for precluding movement of Work pieces from supported position on said chain to positions forwardly of such means whereby to lodge between the conveyor chain and the closing plate and access door, said dam means being in the form of a bafe mounted on said door and having a lower edge disposed in closely spaced relation to said conveyor chain when the access door is closed.

5. The assembly as defined in claim 4 wherein said baffle is hingedly mounted on said access door whereby it is movable into closely spaced relation with the access door when the latter is moved to open position.

6. In a centrifugal blasting machine having a frame, a conveyor chain for supporting work pieces and a front shaft assembly over which the conveyor chain is trained, a closing plate guidably mounted on said frame for movement rectilinearly thereof below said conveyor chain, said closing plate being in the form of a rigid, flat plate and being movable between a closed position in which the outer edge thereof is disposed forwardly of said conveyor chain and front shaft assembly and an open position in which such edge is disposed rearwardly of said front shaft assembly to expose the same and place the closing plate in such position as to be protected from accidental damage.

7. In a centrifugal blasting machine having a frame, a conveyor chain for supporting work pieces and a front shaft assembly over which the conveyor chain is trained, a generally vertical access door guidably mounted on said frame for movement between a closed position in which the lower edge of the access door is positioned below and forwardly of said front shaft assembly and an open position in which such edge is spaced above the conveyor chain and front shaft assembly, a bailie plate carried by said door angling inwardly thereof and having a lower edge disposed in close adjacency to said conveyor chain rearwardly of said front shaft assembly when the door is closed.

8. In a centrifugal blasting machine having a frame, a conveyor chain for supporting work pieces and a front shaft assembly over which the conveyor chain is trained, a generally vertical access door guidably mounted on said frame for movement between a closed position in which the lower edge of the access door is positioned below and forwardly of said front shaft assembly and an open position in which such edge is spaced above the conveyor chain and front shaft assembly, a baffle plate carried by said door angling inwardly thereof and having a lower edge disposed in close adjacency to said conveyor chain rearwardly of said front shaft assembly when the door is closed, said bafe being hingedly mounted on said door and said frame including a portion disposed in the path of movement of said baffle as the ldoor is moved to its open position camming said baffle into substantially coplanar relation with said door.

9. In a centrifugal blasting machine having a frame, a conveyor chain for supporting work pieces and a front shaft assembly over which the conveyor chain is trained, a closing plate guidably mounted on said frame for movement rectilinearly thereof below said conveyor chain, said closing platebeing in the form of a rigid, flat plate and being movable between a closed position in which the outer edge thereof is disposed forwardly of said conveyor chain and front shaft assembly and an open position in which such edge is disposed rearwardly of said front shaft assembly to expose the same and place the closing plate in such position as to be protected from accidental damage, and means for moving said closing plate between open and closed positions, said means including a pair of shafts rotatably carried by said frame below said closing plate and within a plane parallel thereto, sprockets xed to each shaft so as to form. two pairs of aligned sprockets on the respective shafts, a chain trained over each` pair of sprockets and having one flight thereof lying closely adjacent the closing plate and fixed at one point thereto, and a fluid motor mounted on said frame and connected to said closing plate to urge the same between its open and closed positions.

l0. In a centrifugal blasting machine having a frame, a conveyor chain for supporting Work pieces and a front shaft assembly over which the conveyor chain is trained, a closing plate guidably mounted on said frame for movement rectilinearly thereof below said conveyor chain, said closing plate being in the form of a rigid, flat plate and being movable between a closed position in which the outer edge thereof is disposed forwardly of said conveyor chain and front shaft assembly and an open position in which such edge is disposed rearwardly of said front shaft assembly to expose the same and place the closing plate in such position as to be protected from accidental darnage, and means for moving said closing plate between open and closed positions, said means including a shaft rotatably carried by said frame outwardly parallel of and extending transversely of said closing plate, a pair of drums fixed to said shaft in widely spaced relation to each other,` a flexible cable associated with each drum for guiding and moving said closing plate, each such cable being wrapped about its respective drum and having its opposite ends fixed to the upper' and lower edge portions, respectively, of the closing plate.

11. In a centrifugal blasting machine having a frame, a conveyor chain for supporting work pieces and a front shaft assembly over which the conveyor chain is trained, a closing plate guidably mounted on said frame for movement rectilinearly thereof below said conveyor chain, said closing plate being in the form of a rigid, Hat plate and being movable between a closed position in which the outer edge thereof is disposed forwardly of said conveyor chain and front shaft assembly and an open position in which such edge is disposed rearwardly of said front shaft assembly to expose the same and place the closing plate in such position as to be protected from accidental damage, and means for moving said closing plate between open and closed positions, said means including an arm fixed to and extending from said closing plate, a pair of guide elements rigid with said frame and sandwiching said arm therebetween, and a iluid motor carried by said frame and connected to said plate.

References Cited in the file of this patent UNITED STATES PATENTS 2,918,758 Barnes Dec. 29, i959 FOREIGN PATENTS 497,428 Canada Nov. 3, 1953 

